


Compatible Lunacy

by OneOfThoseThings



Category: Doctor Who (2005)
Genre: (at best), Accidental Plot, Accidental Relationship, Boundary Issues, Communication Difficulties, Cotton Candy Fluff, Didn't Know They Were Dating, F/M, Fluff and Humor, Friendship/Love, Implied Sexual Content, Rating Rounded Up (for Safety), The Author Regrets Nothing, a distinct lack of shame
Language: English
Status: Completed
Published: 2021-01-19
Updated: 2021-01-19
Packaged: 2021-03-17 19:27:18
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,944
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28854285
Author URL: https://archiveofourown.org/users/OneOfThoseThings/pseuds/OneOfThoseThings
Summary: After Martha’s wedding, Donna and the Doctor have a casual chat. Like really casual. Possibly too casual.(Direct Sequel toJust Act Natural.)
Relationships: Tenth Doctor/Donna Noble
Comments: 8
Kudos: 73





	Compatible Lunacy

**Author's Note:**

> Thanks, as usual, to my beta reading champion, Quercusrobur!

The Doctor barged back into the TARDIS and immediately started examining every inch of the console to make sure nothing new had been tampered with. 

“Are you _sure_ Time Lords aren’t related to cats?” Donna asked. “My cat used to check the whole house just like that when we brought him back from the vet.” 

“Yes, I’m sure! Stop asking!” The Doctor made another pass, looking for anything amiss.

Donna rolled her eyes, but headed over to the main column to greet the ship. “Did you have a nice rest?” The whatever-it-was in the column seemed to puff more pointedly, which she assumed was a good sign. “Yes, the wedding was very nice.” She noticed the Doctor was watching her. “…What?” 

The Doctor gave himself a little shake, and set them back off into the vortex. “Come over here for a minute, I’m going to biolock you out of the higher system settings.”

“Hmmm, think I might pass on that.” Donna picked up the bag she’d borrowed from Martha. “And you should be thanking me! Got you to that wedding on time! No one died or was kidnapped! Nothing blew up!” She put a hand on her hip. “I should get a gold medal!” 

The Doctor puffed up defensively. “I followed all the customs!” He looked a bit hurt, of all things. “Was it really _that_ difficult?” 

Donna’s stupid soft heart immediately got the better of her. “No, Spaceman, you did very well. Blended right in!” He gave her a doubtful look and even she couldn’t hold that line. “Well, I don’t think anyone guessed outright that you’re a time-travelling alien. So we didn’t out Martha! And that was the goal, right?” She gave him a bright smile and a hug for good measure. The Doctor hugged her back like he always did, but when she pulled back he was still frowning. “What?”

“Why did you tell Tom we were married?” he asked. “That’s not an obligatory human function.” 

“Um. Caught that, did you?” Donna shrugged. “He just sort of assumed. Like everyone seems to.” 

But the Doctor wasn’t letting that one go so easily. “Why didn’t you let me correct him?” 

Donna sighed. “Listen, it’s― it’s a bit complicated, isn’t it? For a new bloke to meet an old bloke, I mean.” 

The Doctor squinted at her. “Are you changing the topic?”

“No, I mean― It’s Martha’s call, yeah? What she does and doesn’t want to tell her husband?” 

The Doctor just seemed more confused. “But why would your marital status be relevant?” 

Donna rolled her eyes so hard it hurt a little. “Not _mine,_ dumbo! _Yours!_ ” 

“What??” 

Donna sighed. “Some blokes― normal― _human_ blokes, I mean― get weird about past…” she waved a hand vaguely, “relationships.” 

“But Martha and I weren’t in a relationship,” the Doctor pointed out immediately.

“Yes, _I_ know that, but, well, that’s not necessarily how it looks, right? I mean people think you and I are married all the time!” 

The Doctor blinked at her. “But you and I _are_ in a relationship.” 

Donna nearly fell over just standing there. “You _what?!_ ” The Doctor gestured between them with his ridiculous blank face. “No, you― Ah, you barmy―! I mean a _proper_ relationship! Not―!” He looked hurt again and she cut off. “Hang on, do you seriously think you and I are in a relationship?!” 

The Doctor looked up like he was actively accessing a database of ‘human terminology’ in his great big alien brain. “Yes. Course.” He looked at her curiously. “Do you _not?_ ”

“Well, I―“ Donna paused, running through her own mental checklist and finding some troubling results. “I just assumed this was, you know,” she gestured vaguely, “how you are!”

“Of course this is ‘how I am,’” the Doctor said, tilting his head too far to the side like a malfunctioning robotic owl. “Is this some sort of riddle?” 

“Yeah, riddle me this, don’t you think it’s weird that we never even snog?” 

The Doctor shrugged. “You said ‘no mating.’”

“What?” Donna gawked. “I said _snog_ not _shag!_ ”

The Doctor gave another strange little shrug, took two steps closer, bent down, and kissed her, apparently taking that as an invitation. 

Donna meant to shove him away. She did. But… well, he wasn’t half bad at it. And it _had_ been awhile… 

One long-fingered hand curled against her cheek and cool lips moved gently against hers and it was momentarily hard to remember what she was objecting to.

Her hip knocked uncomfortably against the control panel, pulling her back out of it. The Doctor backed off just as smoothly, resuming his usual wide-eyed staring like he was waiting for her to assess a new treat. 

Donna could feel herself staring right back. “Are you _seriously_ saying the only reason we haven’t been shagging this whole time is because I haven’t _asked?_ ” 

The Doctor frowned. “Not this _whole_ time. But… if you’d like to…?” He offered a hand, a bit awkwardly. 

“What?!” Donna looked at his hand, up at his face, back to his hand, and up to his face again. “Just like _that?!_ ” 

He pulled a confused face. “We’ve been ―what’s that phrase you use?― dating?― for months. I’ll have to defer to you on the standard timeline.” 

Donna could feel her eyes bulging, but couldn’t quite seem to stop it. “But you― you _never_ said!”

He cocked his head. “Is there normally some sort of formal announcement? We share food, grooming, a bed― you do realize I don’t actually have to sleep half as much as you humans, yes?” 

“Oh, sure, that’s why you pass out like a coma patient every time!” Donna rolled her eyes, but wrenched herself back on track. “Never mind all that! _You_ said you didn’t want to complicate things!” 

“Well,” he said, staring with his wide eyes. “It’s _not_ complicated, this… Is it?” 

“ _I_ didn’t even know we were doing it!” Donna burst out. 

“Oh.” That hurt look was back. “Have I…? Should I stop?” 

“What? No!” Donna didn’t even have to think about it. “You’re― Of course not!” His hurt look flipped back to baffled, and she was having a little trouble keeping up with it herself. “I just― You realize _I’m_ not asexual, right? Doesn’t that make us incompatible or something?” 

The Doctor blinked at her. “Why would it?” 

Donna threw her hands out. “Because _you’re_ asexual!” 

He seemed confused. “Only reproductively. Not as an orientation.”

“What?!” Donna roared. “Since when?!? No, never mind that― Why _don’t you_ think it’s weird that we’re not having sex?!”

The Doctor shrugged. “You said ’no mating.’” 

“So you just― what― took it off the table and carried on?!” 

He shrugged again. “You were very clear.” 

“But― But―!“ For the life of her, Donna couldn’t think of what to say to that. “Really?!”

The Doctor gave a strange bobbly nod. “There are many different types of relationships.”

“I’m pretty sure both people knowing they’re in a relationship is pretty standard!” Donna pointed out, but she was already getting distracted again. “…Does this mean you’d _want_ to have sex? With me, I mean?”

Infuriatingly, the Doctor shrugged again. “If you’d like.”

“No, don’t give me that!” Donna pressed. “I’m asking if _you’d_ like it! Do _not_ shrug at me again!” 

His shoulders twitched, but he only said, “Sure. Course. But only if you―“

Donna yanked him down into a kiss. Just to see, really. It certainly wasn’t a panic move. 

The Doctor didn’t seem to think anything of it, kissing her back as casually as they shared anything else. 

Well, perhaps ‘casual’ wasn’t the word. He bent down to meet her, cool fingers tracing her jaw and cheek, and it had that underlying, unspoken trust that he always seemed to have in her. And she’d always trusted him right back. 

They really _might_ be compatible types of lunatics. 

After a minute or two (or three), Donna had completely lost track of her objections and was trying to work out whether there was a safe space to brace up against the console without launching them into some alternate universe or whatever. One of the Doctor’s hands moved down next to hers, brushing the inside of her wrist, and that really shouldn’t have been so distracting. 

Something that was either a joystick or that bicycle pump jabbed into her when she tried to get after that hand and she shifted around, trying to find a better position. She got a grumbling objection from the ship and the sharp feeling that she was heading the right way for a zap. 

The Doctor pulled back, wincing. “Probably not the best place to lean,” he mumbled and yanked his own hand back, shaking it out and hissing. “I’m going! Don’t _shock_ me!” He backed off a step, and offered that same hand. “I think that was the warning.” 

Donna took his hand automatically and then hesitated. “You’re, um, not doing this out of some weird sense of obligation, are you?” 

The Doctor gave her a level-eyed look. “Yes, Donna. I assume that you’d like to be sexually serviced in exchange for the back rub earlier.”

“Oh, shut up!” Donna snatched his hand more firmly, pulling herself up the rest of the way. “Who knows with you!” 

“I’m over nine hundred years old, you know, I’m not going to be _tricked_ into having sex with you!” the Doctor started up, but didn’t take his hand back. 

“OK, no more age talk,” Donna said and then gave him a skeptical look up and down. “We _are_ talking about the same thing here, aren’t we?” He certainly _seemed_ to have the same bits.

“Yes, it’s basically the same as with seahorses, right?” 

Donna wrenched her head up suspiciously. “What?!” 

The Doctor had the absolute nerve to smile brightly at her. “Over _nine hundred_ years old, Donna! I _know_ what we’re talking about!” 

“ _What_ did I _just_ say about mentioning your age?!” Donna griped, but tugged him along all the same. “If we get into this and you start whipping out tentacles I _will_ kick you out!” 

The Doctor nodded. “Tentacles stay in, got it.”

She gave him a sharp look, but pushed open the door to her room. 

* * *

A respectable forty-eight minutes and thirteen seconds later, they were sprawled out in Donna’s bed and Donna was feeling much more confident that the Doctor wasn’t just humoring her. 

“I can’t believe we could’ve been doing this the whole time,” Donna said, having a little trouble catching her breath. “You’re not half bad at it, for someone who doesn’t even think to ask!” 

“Should I periodically re-ask you questions that you’ve already answered to see if the answer has changed?” the Doctor mused. His breathing was insultingly even, but at least his hair was a riot. And he seemed to be having trouble lifting his head. 

“Apparently!” Donna said, rolling onto her stomach and half on top of him. “Oh, you’re still cold,” she noted, and sidled her way the rest of the way on top. “Oh, that’s a bit nice, actually.” She stretched and wriggled, working out how to maximize contact, like lying on cool tiles in summer. 

“Comfy?” the Doctor asked drily, letting her slide her arms under his. 

“Quite,” she agreed and tilted her head to the side to save him from a sharp chin in the chest. 

After a few minutes he shifted and asked, “Am I now allowed to offer oral sex in exchange for back rubs?”

“Maybe in a bit,” Donna mumbled, halfway to dozing already.

“Isn’t it rude to fall asleep on top of someone right after sex?” the Doctor asked. 

“Yep,” Donna said and dropped off.

**Author's Note:**

> I’m also on [tumblr](https://1-of-those-things.tumblr.com/).


End file.
